Baby Pacman problem

dyno

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My baby pacman has started acting up, when you start the game you see the dots, the ghosts, and baby pacman but the actaul maze is missing. I am thinking a corrupt rom on the vidiot board, am I heading in the right direction. I know baby pacs are notorious for having problems
 
Is there any acid damage on the vidiot? Pull the roms and look to see if any of the socket pins are green. If you can see some green pins you can bet some of the pins have corroded off under the socket. Best practice on the vidiots are to replace all the sockets. I know its alot of sockets but many times they look good but once you pull them it reveals some pretty significant acid damage. The center of the board gets it the worst since the battery sits right above it.
 
Finally got around to working on the baby pac again, one of the sockets on the vidiot board had some corrosion on it just like Riptor said so thanks for the info on that. I replaced the socket and the game works again but the only thing now is when you leave video mode to go to pinball mode the screen shows the 4 power pellet screen which is correect but there are cherries floating across the screen and pinball mode doesn't work and the game just stays like that. It did this occassionally in the past but now it does it all the time. Sound like a rom issue?
 
Did you replace all the sockets on the vidiot?
I have seen that issue before and it was a socket issue. Of course it could also be a rom problem as well. If you have a programmer go ahead and verify all those roms.
 
I haven't replaced all the sockets, but I will try that and if that doesn't work I will put my burner I bought recently to work and see if that works.
 
If you find rom(s) that dont compare it doesnt mean they are bad. I know there are at least two different rom versions out there.
 
Sockets not the problem, now would it be a problem with an eprom on the vidiot board or the main pcb? When the game is in attract mode all the lights on the playfield light up but as soon as you start the game only the letter F and the letter T on the playfield light up and flash. Then when you play the maze part and try escape to go to pinball mode the screen with the 4 power pellets shows and cherries float across the screen and the game is stuck in that screen and does nothing else. Which board should I try to burn new eproms for? On the main board U2 is a 2532 and U6 is a 2732, can I use a 2732 in place of the 2532? If I can do that I assume i would need to change a few jumper wires around?
 
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sounds like the outhole switch is not activating when the pinball drains. verify that the outhole switch is making contact when the ball is sitting in the outhole kicker. this is a very common problem on baby pac
 
Crap, dokert is right. My machine did this very thing once after moving it. Adjusted the switch and that fixed it. I had forgotten about the cherries floating across the screen. when that happened.
 
Problem solved. One of the connectors from the power board that goes to the playfield was not connected all the way on the power pcb so something wasn't making proper contact, plugged the connector in all the way and bingo the game is working fine. Something that simple. Thanks for all the help :)
 
Every time I see a Baby-Pac I cringe. Those were the worst games I think I have ever worked on. It's been over 20 years since I was last inside one and I still cringe at the thought of them.
 
My baby pac is acting up in the same manner. She's in the garage and I'm hoping the cold weather but it's been finicky since the day I got it. Guy said it needed repinned/reflowed. Anytime I move it I have to giggle come of the connections.

Right now I'm having the same problem, no maze is showing and if I exit to maze to play pinball the screen goes to garbage. How do I check this outhole switch thingamabob?
 
Hmm, I'm also only getting 8 flashes from the vidiot board. Reading the manual, that possibly a bad TMS9928 at U16? I reseated but no change.
 
Vidiot flashes are generated by both the video and audio sections on the board and both are wired in parallel to the LED. This means that the video flashes are not dependent on the audio flashes and simply counting the flashes without more investigation may not be telling you what components are bad. From the manual:

"Both the Sound uP and Video uP on the Vidiot use the same LED for Self-Test. The Sound uP goes first while the Video uP waits for about 30 seconds. If the LED comes on after RESET and stays on both the Sound and Video sections of the Vidiot are not functioning. If the LED stays on or off for about 3 seconds then starts flashing the Sound section has a problem. If the LED flashes then stays on or off after about 3 seconds the Video section of the Vidiot has a problem."

Pressing the sound test switch SW2 allows you to see if the sound section is working properly and if those flashes are contributing to the total flash count during boot.

viperrwk
 
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